Unlock mac with apple watch unable to communicate

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Question:

Question: Mac unable to communicate with your Apple Watch

My Watch was unlocking my 14" MacBook Pro (M1) OS 12.2.1 Watch OS 8.4.2 iPhone iOS 15.3.2 until it wasn't. I opened System Preferences and found use your Apple Watch to unlock your Mac is unchecked (without notice, it had been checked). Attempts to reinstate it generate the message "Mac unable to communicate with your Apple Watch, make sure your Apple Watch is unlocked and on your wrist, and you iPhone is unlocked.

Watch is on wrist, signed into my AppleID (as are my Mac and iPhone). My Watch and iPhone both are unlocked--same error message.

I have tried restarting all three devices. No luck.

I went to the hassle of unpairing and repairing my Apple Watch. No luck.

I logged into iCould.com and "Find" locates my Mac, my Watch, and my iPhone.

So why can't my Mac communicate with my Apple Watch all of the sudden?

MacBook Pro 14″, macOS 12.2

Posted on Feb 19, 2022 11:08 AM

User profile for user: Murph Sewall

Question: Mac unable to communicate with your Apple Watch

Question:

Question: Your Mac was unable to communicate with your Apple Watch.

When I installed WatchOS 7 on my Series 4, I had terrible problems with the battery life. Usually when I put my watch on the charger at night, I would have about 50% battery left. After the update, my watch would last maybe 8-10 hours and then I'd start getting the 10% battery warnings. One of the solutions I found online was to unpair my watch from my iPhone and then pair it again. Doing this appears to have fixed the battery drain problem, but now I can not turn on the option to unlock my MacBook Pro with my watch.

To enable unlock with my watch I go to System Preferences -> Security & Privacy and tick the "Use your Apple Watch to unlock apps and your Mac." Sometimes I get prompted for my password to unlock my disk and sometimes I don't. In either case, "Turning on..." with a spinning icon is displayed for a few seconds, and then I get an error message from the subject of this post. It also says to "Make sure your Apple Watch is unlocked and on wrist, and your iPhone is unlocked."

This was working before I unpaired and re-paired my watch. I have tried all of the suggestions that searching for this error message brings up, including restarting everything, making sure everything is on the same WiFi network, disabling/enabling handoff, restarting bluetooth, disabling/enabling auto-unlock of watch from phone, logging my MacBook out of iCloud and back in again, etc. Nothing seems to help me get this option enabled again.

I would really like to get this option turned back on again. Any other suggestions?

MacBook Pro 15″, macOS 10.15

Posted on Sep 21, 2020 6:59 AM

Answer:

Answer:

This isn’t my solution but was posted in another thread by stoska992, but it worked for me!

I've finally fixed it! I found a bunch of errors related to "AutoUnlock" in the Console that was hinting to me that there was some invalid state on my Mac with keys and plists not being reset properly. 

Steps (follow at your own discretion)

  1. Open "Keychain Access"
  2. In "View", enable "Show Invisible Items"
  3. Search for "Auto Unlock"
  4. You should see a whole bunch of application passwords for "Auto Unlock: XXXX's ..."
  5. Select all records and delete (this will reset/disable auto unlock on other Macs if you use multiple Macs)
  6. Whilst still in "Keychain Access", search for "AutoUnlock" (no space)
  7. There should be 4 entries for "tlk" "tlk-nonsync" "classA" "classC"
  8. Select 4 records and delete (don't worry if they re-appear, the system repairs this automatically)
  9. Open "Finder" and navigate to "~/Library/Sharing/AutoUnlock"
  10. There should be two files "ltk.plist" and "pairing-records.plist"
  11. Delete both files
  12. Open "System Preferences" and try enabling auto unlock. You may need to enable it twice, the first attempt will fail.

Posted on Sep 25, 2020 9:07 PM

  1. Make sure that your devices are set up as follows:

    • Your Mac has Wi-Fi and Bluetooth turned on.

    • Your Mac and Apple Watch are signed in to iCloud with the same Apple ID, and your Apple ID is using two-factor authentication.

    • Your Apple Watch is using a passcode.

  2. Choose Apple menu > System Preferences.

  3. Click Security & Privacy, then click General.

  4. Select “Use Apple Watch to unlock apps and your Mac.”

    If you have more than one Apple Watch, select the watches you want to use to unlock your apps and Mac.

If you don’t have two-factor authentication turned on for your Apple ID, follow the onscreen instructions, then try selecting the checkbox again. See the Apple Support article Two-factor authentication for Apple ID.

Why isn't my Apple Watch communicating with my Mac?

Make sure that your devices are set up as follows: Your Mac has Wi-Fi and Bluetooth turned on. Your Mac and Apple Watch are signed in to iCloud with the same Apple ID, and your Apple ID is using two-factor authentication. Your Apple Watch is using a passcode.

Why does it say unable to communicate with Apple Watch?

Turn on Bluetooth and Wi-Fi On and Off If your iPhone is still unable to communicate with your Apple Watch, confirm that your Bluetooth and Wi-Fi are enabled on both your Apple Watch and your iPhone. If they are turned on, switch them off and turn them back on.

Why won't my Apple Watch unlock my Mac anymore?

If you're having difficulty getting Auto Unlock to work, try these solutions: In Security & Privacy preferences, deselect ”Use your Apple Watch to unlock apps and your Mac,” then restart your Mac and turn this setting back on. Make sure that your Mac isn't using Internet sharing or screen sharing.